modules/slideshow/slideshow.module

<?php
// $Id: slideshow.module,v 1.19 2007/04/21 16:53:34 timcn Exp $

/**
 * @file
 * slideshow.module provides basic slideshow capabilities. It transforms images
 * attached to nodes to a JavaScript enhanced slideshow. If the user does not have
 * JavaScript enabled, it degrades to a "regular" slideshow where the "next"
 * link points to the next image and a whole new page is loaded.
 */

// Define constants for slideshow settings
define('SLIDESHOW_LOCATION_DEFAULT', 0);
define('SLIDESHOW_LOCATION_NONE', 1);
define('SLIDESHOW_LOCATION_ABOVE', 2);
define('SLIDESHOW_LOCATION_BELOW', 3);
define('SLIDESHOW_LOCATION_TAG', 4);

define('SLIDESHOW_ALIGN_DEFAULT', 0);
define('SLIDESHOW_ALIGN_FULL', 1);
define('SLIDESHOW_ALIGN_LEFT', 2);
define('SLIDESHOW_ALIGN_RIGHT', 3);


/**
 * Implementation of hook_menu().
 */
function slideshow_menu($may_cache) {
  $items = array();

  if ($may_cache) {
    $items[] = array(
      'path' => 'admin/settings/slideshow',
      'title' => t('Slideshow'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('slideshow_admin_settings'),
      'access' => user_access('administer site configuration'),
      'description' => t('Change default settings for slideshows, such as the image dimensions.')
    );
  }

  return $items;
}


/**
 * Implementation of hook_perm().
 */
function slideshow_perm() {
  return array('configure slideshows');
}


/**
 * Implementation of hook_form_alter().
 */
function slideshow_form_alter($form_id, &$form) {
  if ($form_id == 'slideshow_node_form' && isset($form['attachments'])) {
    $form['attachments']['#title'] = t('Images');
    $form['attachments']['#collapsed'] = FALSE;
    
    // Preserve the title of the file, even if it's empty.
    foreach ($form['#node']->files as $key => $file) {
      $form['attachments']['wrapper']['files'][$key]['description']['#default_value'] = $file->description;
      
      if ($form['attachments']['wrapper']['files'][$key]['description']['#default_value'] == $file->filename) {
        $form['attachments']['wrapper']['files'][$key]['description']['#default_value'] = '';
      }
    }
  }

  // Add the ability to enable/disable the slideshow for a content type
  if ($form_id == 'node_type_form' && isset($form['identity']['type'])) {
    $form['workflow']['slideshow'] = array(
      '#type' => 'radios',
      '#title' => t('Slideshow'),
      '#description' => t('If enabled, images attached to the post are displayed in the form of a slideshow.'),
      '#default_value' => variable_get('slideshow_'. $form['#node_type']->type, 0),
      '#options' => array(t('Disabled'), t('Enabled')),
    );
  }

  // If this is a node form...
  if (isset($form['type']) && $form['type']['#value'] .'_node_form' == $form_id) {
    // ... add the slideshow settings page
    if (variable_get('slideshow_'. $form['type']['#value'], FALSE) && user_access('configure slideshows')) {
      _slideshow_node_form($form);
    }
  }
}

/**
 * Implementation of hook_settings()
 */
function slideshow_admin_settings() {
  $maximum_size = variable_get('upload_max_resolution', 0);
  if (!preg_match('~^[1-9]\d*x[1-9]\d*$~', $maximum_size)) {
    $maximum_size = t('not set');
  }

  $form['slideshow_default_location'] = array(
    '#type' => 'select',
    '#title' => t('Default display location'),
    '#description' => t('Select where the slideshow appears by default. If you select %above, users have to explicitly active the slideshow for each post.', array('%above' => t('Above'))),
    '#options' => array(
      SLIDESHOW_LOCATION_NONE => t('Nowhere'),
      SLIDESHOW_LOCATION_ABOVE => t('Above'),
      SLIDESHOW_LOCATION_BELOW => t('Below'),
      SLIDESHOW_LOCATION_TAG => t('Within')
    ),
    '#default_value' => variable_get('slideshow_default_location', SLIDESHOW_LOCATION_ABOVE),
  );

  $form['slideshow_default_align'] = array(
    '#type' => 'select',
    '#title' => t('Default alignment'),
    '#description' => t('Select how the slideshow box should be displayed by default.'),
    '#options' => array(
      SLIDESHOW_ALIGN_FULL => t('Full width'),
      SLIDESHOW_ALIGN_LEFT => t('Left'),
      SLIDESHOW_ALIGN_RIGHT => t('Right')
    ),
    '#default_value' => variable_get('slideshow_default_align', SLIDESHOW_ALIGN_FULL),
  );

  $form['slideshow_default_dimensions'] = array(
    '#type' => 'textfield',
    '#title' => t('Default image size'),
    '#default_value' => variable_get('slideshow_default_dimensions', '640x480'),
    '#size' => 20,
    '#maxlength' => 20,
    '#description' => t('The maximum size of images displayed in a slideshow. Cannot be bigger than the maximum image size for upload module (which is @maximum-size).', array('@maximum-size' => $maximum_size)),
    '#field_suffix' => t('<kbd>WIDTHxHEIGHT</kbd>'),
  );

  $form['slideshow_image_path'] = array(
    '#type' => 'textfield',
    '#title' => t('Slideshow image path'),
    '#default_value' => variable_get('slideshow_image_path', 'slideshow'),
    '#field_prefix' => variable_get('file_downloads', FILE_DOWNLOADS_PUBLIC) == FILE_DOWNLOADS_PUBLIC ? file_create_url('') : '&lt;'. t('Private') .'&gt;/',
    '#description' => t('Subdirectory in the global file directory where resized images for slideshows will be stored.'),
  );

  return system_settings_form($form);
}

function slideshow_admin_settings_validate($form_id, $form_values) {
  // Test for a valid image size
  if (!preg_match('~^[1-9]\d*x[1-9]\d*$~', $form_values['slideshow_default_dimensions'])) {
    form_set_error('slideshow_default_dimensions', t('The specified default slideshow image size is invalid.'));
  }
}

/**
 * Retrieve the directory where slideshow images are stored in.
 */
function slideshow_image_directory() {
  $slideshow_path = file_create_path(variable_get('slideshow_image_path', 'slideshow'));

  // Make sure that the directory exists
  if (!file_check_directory($slideshow_path, FILE_CREATE_DIRECTORY)) {
    drupal_set_message(t("Slideshow images can't be created because the directory %directory has not been properly configured.", array('%directory' => $slideshow_path)), 'error');
  }

  return $slideshow_path;
}

/**
 * Helper function for hook_form_alter(). Adds form elements to node submission forms
 */
function _slideshow_node_form(&$form) {
  // Remove the body requirement
  if (isset($form['body_filter']) && isset($form['body_filter']['body'])) {
    $form['body_filter']['body']['#required'] = FALSE;
  }

  $form['slideshow'] = array(
    '#type' => 'fieldset',
    '#access' => user_access('attach images as slideshow'),
    '#title' => t('Slideshow settings'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
    '#description' => t('Attached images are displayed in the form of a slideshow.'),
    '#weight' => 35,
    '#suffix' => '</div>',
    '#tree' => TRUE,
  );

  // Fetch the values for the <Default: ...> select values
  $location = variable_get('slideshow_default_location', SLIDESHOW_LOCATION_ABOVE);
  $options = array(
    SLIDESHOW_LOCATION_NONE => t('Nowhere'),
    SLIDESHOW_LOCATION_ABOVE => t('Above'),
    SLIDESHOW_LOCATION_BELOW => t('Below'),
    SLIDESHOW_LOCATION_TAG => t('Tag')
  );

  $form['slideshow']['location'] = array(
    '#type' => 'select',
    '#title' => t('Display location'),
    '#description' => t('Select where the slideshow appears. To specify a place within the content, use <var>[slideshow]</var> and select the appropriate location here.'),
    '#options' => array(SLIDESHOW_LOCATION_DEFAULT => '<'. t('Default') .': '. $options[$location] .'>') + $options,
    '#default_value' => isset($form['#node']->slideshow) ? $form['#node']->slideshow['location'] : SLIDESHOW_LOCATION_DEFAULT,
  );

  $align = variable_get('slideshow_default_align', SLIDESHOW_ALIGN_FULL);
  $options = array(
    SLIDESHOW_ALIGN_FULL => t('Full width'),
    SLIDESHOW_ALIGN_LEFT => t('Left'),
    SLIDESHOW_ALIGN_RIGHT => t('Right')
  );

  $form['slideshow']['align'] = array(
    '#type' => 'select',
    '#title' => t('Alignment'),
    '#description' => t('Select whether the slideshow box is displayed with full width or floated on the left or right side.'),
    '#options' => array(SLIDESHOW_ALIGN_DEFAULT => '<'. t('Default') .': '. $options[$align] .'>') + $options,
    '#default_value' => isset($form['#node']->slideshow) ? $form['#node']->slideshow['align'] : SLIDESHOW_ALIGN_DEFAULT,
  );

  $form['slideshow']['dimensions'] = array(
    '#type' => 'textfield',
    '#title' => t('Image size'),
    '#default_value' => isset($form['#node']->slideshow) ? $form['#node']->slideshow['dimensions'] : '',
    '#size' => 20,
    '#maxlength' => 20,
    '#description' => t('The maximum size of images displayed in a slideshow. Leave blank to use the default size (<kbd>@default-size</kbd>).', array('@default-size' => variable_get('slideshow_default_dimensions', '640x480'))),
    '#field_suffix' => t('<kbd>WIDTHxHEIGHT</kbd>'),
  );

  if (!isset($form['#validate'])) {
    $form['#validate'] = array();
  }
  $form['#validate']['_slideshow_node_form_validate'] = array();
}

function _slideshow_node_form_validate($form_id, $form_values) {
  // Test for a valid image size or for an empty value
  if (!empty($form_values['slideshow']['dimensions']) && !preg_match('~^[1-9]\d*x[1-9]\d*$~', $form_values['slideshow']['dimensions'])) {
    form_set_error('slideshow][dimensions', t('The specified slideshow image size is invalid.'));
  }
}

/**
 * Implementation of hook_nodeapi()
 */
function slideshow_nodeapi(&$node, $op, $teaser) {
  if (variable_get('slideshow_'. $node->type, FALSE)) {
    // Only act if slideshow is activated for this content type

    if (isset($node->slideshow)) {
      // determine if this node's slideshow values are not default
      $default_settings = ($node->slideshow['location'] == SLIDESHOW_LOCATION_DEFAULT && $node->slideshow['align'] == SLIDESHOW_ALIGN_DEFAULT && empty($node->slideshow['dimensions']));
    }
    else {
      $default_settings = TRUE;
    }

    switch ($op) {
      case 'delete':
        slideshow_delete_images($node);
        slideshow_delete_records($node);
        break;
      case 'delete revision':
        slideshow_delete_revision_record($node);
        break;
      case 'update':
        slideshow_update_images($node);
        if ($node->revision && !$default_settings) {
          slideshow_insert_record($node);
        }
        else {
          slideshow_delete_revision_record($node);
          if (!$default_settings) {
            slideshow_insert_record($node);
          }
        }
        break;
      case 'insert':
        slideshow_update_images($node);
        if (!$default_settings) {
          slideshow_insert_record($node);
        }
        break;
      case 'load':
        return slideshow_load_record($node);
        break;
      case 'view':
        slideshow_view($node, $teaser);
        break;
    }
  }
}

/**
 * Add a slideshow settings record for a node revision.
 *
 * @param $node The node revision whose slideshow record should be added. The
 *   slideshow property must be set.
 */
function slideshow_insert_record(&$node) {
  db_query("INSERT INTO {slideshow} (nid, vid, location, align, dimensions) VALUES (%d, %d,%d, %d, '%s')", $node->nid, $node->vid, $node->slideshow['location'], $node->slideshow['align'], $node->slideshow['dimensions']);
}

/**
 * Load a slideshow settings record for a node.
 *
 * @param $node The node revision whose slideshow record should be loaded.
 * @return The slideshow settings for the node. If no record is available, the
 *   default values are returned.
 */
function slideshow_load_record(&$node) {
  $result = db_fetch_array(db_query("SELECT location, align, dimensions FROM {slideshow} WHERE nid = %d AND vid = %d;", $node->nid, $node->vid));

  if (empty($result)) {
    $result = array(
      'location' => SLIDESHOW_LOCATION_DEFAULT,
      'align' => SLIDESHOW_ALIGN_DEFAULT,
      'dimensions' => '',
    );
  }

  return array('slideshow' => $result);
}

/**
 * Delete a slideshow settings record for a node revision.
 *
 * @param $node The node revision whose slideshow record should be deleted.
 */
function slideshow_delete_revision_record(&$node) {
  db_query("DELETE FROM {slideshow} WHERE nid = %d AND vid = %d;", $node->nid, $node->vid);
}

/**
 * Delete all slideshow settings record for a node.
 *
 * @param $node The node whose slideshow records should be deleted.
 */
function slideshow_delete_records(&$node) {
  db_query("DELETE FROM {slideshow} WHERE nid = %d;", $node->nid);
}

/**
 * Delete all slideshow images associated with the node.
 *
 * @param $node The node whose slideshow images should be deleted.
 */
function slideshow_delete_images(&$node) {
  if ($node->files) {
    $path = slideshow_image_directory();

    foreach ($node->files as $file) {
      file_delete($path .'/'. $file->filename);
    }
  }
}

/**
 * Update the slideshow images for a node. Old images will be deleted and new ones
 * will be added. If the dimensions change, images are recalculated.
 *
 * @param $node The node whose slideshow images should be updated.
 */
function slideshow_update_images(&$node) {
  $path = slideshow_image_directory();

  // Get the image dimensions for this node (or the default dimensions if there are none).
  $dimensions = !empty($node->slideshow['dimensions']) ? $node->slideshow['dimensions'] : variable_get('slideshow_default_dimensions', '640x480');

  // Check if the previous revision contains files that this revision doesn't
  if ($node->revision) {
    // List all files for this node (regardless of their revision)
    $result = db_query("SELECT fid, filename, filemime FROM {files} WHERE nid = %d", $node->nid);

    // Loop through all the files this node has in any revision
    while ($file = db_fetch_object($result)) {
      // Don't treat non-image files
      if (strpos($file->filemime, 'image/') !== 0) continue;
      $image = $path .'/'. $file->filename;

      // When the file is not present in the current revision, simply delete it
      if (!isset($node->files[$file->fid])) {
        file_delete($image);
      }
    }
  }

  // create all images in the currently active revision
  if (!empty($node->files)) {
    // Determine if the file size has to be changed
    $result = db_fetch_array(db_query("SELECT dimensions FROM {slideshow} WHERE nid = %d ORDER BY vid DESC LIMIT 1", $node->nid));
    $recreate = !(($result && $result['dimensions'] == $dimensions) || (!$result && empty($node->slideshow['dimensions'])));

    $dimensions = explode('x', $dimensions);

    // Loop through all files
    foreach ($node->files as $file) {
      $file = (object) $file;
      // Don't treat non-image files
      if (strpos($file->filemime, 'image/') !== 0) continue;

      // Create the slideshow image path
      $destination = $path .'/'. $file->filename;

      // Remove the file if it is completely removed or recreated
      if ($file->remove || $recreate) {
        file_delete($destination);
      }

      // If the file is not removed and the file doesn't exist or should be recreated
      if (!$file->remove && (!is_file($destination) || $recreate)) {
        slideshow_create_image($file->filepath, $destination, $dimensions[0], $dimensions[1]);
      }
    }
  }
}

/**
 * Create an image with the given parameters. If the image can't be scaled,
 * try to copy it (e.g. if the destination image size is larger than the actual file).
 *
 * @param $source The path to the source image.
 * @param $destination The destination path.
 * @param $width The new width.
 * @param $height The new height.
 */
function slideshow_create_image($source, $destination, $width, $height) {
  if (!image_scale($source, $destination, $width, $height)) {
    if (!file_copy($source, $destination, FILE_EXISTS_ERROR)) {
      drupal_set_message(t('The file %file could not be created.', array('%file' => $destination)));
    }
  }
}

/**
 * Add the slideshow to the node.
 *
 * @param $node The node the slideshow should be displayed for.
 */
function slideshow_view(&$node) {
  $location = $node->slideshow['location'];
  if ($location == SLIDESHOW_LOCATION_DEFAULT) {
    $location = variable_get('slideshow_default_location', SLIDESHOW_LOCATION_ABOVE);
  }

  // If there are no files or the slideshow is set to hidden, don't continue processing
  if (empty($node->files) || $location == SLIDESHOW_LOCATION_NONE) return;

  $images = array();
  $files = array();

  // First, sort the file attachments by their type (image vs. non-image)
  foreach ($node->files as $key => $file) {
    if (strpos($file->filemime, 'image/') === 0) {
      $images[] = $file;
      $node->files[$key]->list = FALSE;
    }
    else {
      $files[$key] = $file;
    }
  }

  // If there are no images attached, don't continue processing
  if (empty($images)) return;

  // Get the base path for all slideshow images
  $path = variable_get('slideshow_image_path', 'slideshow');

  // Construct the settings array
  $settings = array(
    'images' => array(),
    'total' => count($images),
    'current' => 0,
    'link' => url('node/'. $node->nid, 'slide=$slideshow$'),
  );

  if (isset($_GET['slide'])) {
    $current = (int)$_GET['slide'];
    $settings['current'] = ($current < 1 || $current > $settings['total']) ? 0 : $current - 1;
  }

  foreach ($images as $key => $image) {
    $settings['images'][$key] = array(
      'src' => file_create_url($path .'/'. $image->filename),
      'title' => check_plain($image->description),
    );
  }

  // Construct the base slideshow element
  $slideshow = array(
    '#type' => 'slideshow',
    '#attributes' => array('class' => 'slideshow', 'id' => 'slideshow-'. $node->nid),
    '#slideshow' => array(
      'settings' => array('slideshow-'. $node->nid => $settings),
      'status' => array(
        'current' => $settings['current'] + 1,
        'total' => $settings['total'],
        'previous' => $settings['current'] <= 0 ? $settings['total'] : $settings['current'],
        'next' => $settings['current'] >= $settings['total'] - 1 ? 1 : $settings['current'] + 2,
      ),
      'url' => 'node/'. $node->nid,
      'title' => $settings['images'][$settings['current']]['title'],
      'image' => $settings['images'][$settings['current']]['src'],
    ),
    '#weight' => 0,
  );
  
  $align = $node->slideshow['align'];
  if ($align == SLIDESHOW_ALIGN_DEFAULT) {
    $align = variable_get('slideshow_default_align', SLIDESHOW_ALIGN_FULL);
  }

  switch ($align) {
    case SLIDESHOW_ALIGN_LEFT:
      $slideshow['#attributes']['class'] .= ' align-left';
      break;
    case SLIDESHOW_ALIGN_RIGHT:
      $slideshow['#attributes']['class'] .= ' align-right';
      break;
    case SLIDESHOW_ALIGN_FULL:
    default:
      $slideshow['#attributes']['class'] .= ' align-full';
  }

  // Determine if the tag location is valid, otherwise set it to the default location
  if ($location == SLIDESHOW_LOCATION_TAG &&
      (!isset($node->content['body']) ||
       empty($node->content['body']['#value']) ||
       strpos($node->content['body']['#value'], '[slideshow]') === FALSE)) {
    $location = SLIDESHOW_LOCATION_ABOVE; // the variable could contain SLIDESHOW_LOCATION_TAG
  }

  // Figure out where to insert the slideshow
  switch ($location) {
    case SLIDESHOW_LOCATION_BELOW:
      $slideshow['#weight'] = 5;
      $slideshow['#attributes']['class'] .= ' location-below';
      $node->content['slideshow'] = $slideshow;
      break;
    case SLIDESHOW_LOCATION_TAG:
      $body = explode('[slideshow]', $node->content['body']['#value']);
      unset($node->content['body']['#value']);
      $slideshow['#attributes']['class'] .= ' location-tag';
      $node->content['body']['above'] = array('#value' => array_shift($body), '#weight' => -5);
      $node->content['body']['slideshow'] = $slideshow;
      $node->content['body']['below'] = array('#value' => implode('', $body), '#weight' => 5);
      break;
    case SLIDESHOW_LOCATION_ABOVE:
    default:
      $slideshow['#weight'] = -5;
      $slideshow['#attributes']['class'] .= ' location-above';
      $node->content['slideshow'] = $slideshow;
  }

  // If the attachment listing is present, overwrite or remove it
  if (isset($node->content['files'])) {
    if (!empty($files)) {
      // Regenerate the attachment listing with the actual (non-image) files
      $node->content['files'] = array(
        '#value' => theme('upload_attachments', $files),
        '#weight' => 50,
      );
    }
    else {
      // No regular files are present in this node
      unset($node->content['files']);
    }
  }
}

function theme_slideshow($element) {
  $slideshow = $element['#slideshow'];
  $status = $element['#slideshow']['status'];

  drupal_add_js(drupal_get_path('module', 'slideshow') .'/slideshow.js');
  drupal_add_css(drupal_get_path('module', 'slideshow') .'/slideshow.css');
  drupal_add_js(array('slideshow' => $slideshow['settings']), 'setting');

  $output = (isset($element['#prefix']) ? $element['#prefix'] : '') .'<div'. drupal_attributes($element['#attributes']) .'>';
  $output .= '<div class="header">';
  $output .=   l(t('Previous'), $slideshow['url'], array('class' => 'previous'), 'slide='. $status['previous']) .' | ';
  $output .=   t('Image !current of !total', array('!current' => '<span class="current">'. $status['current'] .'</span>', '!total' => '<span class="total">'. $status['total'] .'</span>')) .' | ';
  $output .=   l(t('Next'), $slideshow['url'], array('class' => 'next'), 'slide='. $status['next']);
  $output .= '</div>';
  $output .= '<img class="image" src="'. $slideshow['image'] .'" />';
  $output .= '<span class="title">'. check_plain($slideshow['title']) .'</span>';
  $output .= '</div>'. (isset($element['#suffix']) ? $element['#suffix'] : '');

  return $output;
}